Trimethylthionaphthene vat dyestuffs



Patented Nov; 25, I930 UNITED STATES? ERWIN I-IOFFA AND HANS HEYNA, or.HQCHsT-QN-TH QMAIN, GERMANY, ASSIGNORS T GENERAL ANILINE woRKs, INC,OFUNEW YORK, N. n, a oonronArloN on DELAWARE V a TRIMETHYLTHIONAPHTHNNE.yA'rDYnsTUFFs V i No Drawing. A pncama filed March so, 1928, Serial No.26e ,'1os,ai1a in Germanyf Ap ril 11, 1927. a

Our present invention relatest o new vat dyestuffs "and process ofpreparing them.

The thioindigo dyestufis substituted in 4:

and 6-position'give dyeings which are partly distinguished by theclearness of their tints and an excellent fastness to boiling. Adyestuff meeting at thesame time the highest requirements asto fastnessto light has, how

i ever, hitherto not been known in this series of dyestuffs.

We have found that the 4-6-7,4-6-7"-hexamethylthioindigo'has anunusually good fastness to light besides the other good tinctorialpropertiespossessed by certain members of this series.

The said dyestufi can'be' obtained by subjecting the3-5-6-trimethylbenzene-1-thioglycollie acid or a substitution productthereof containing in 2-position the carboxyl-, carboxylic acid-amideorcyanogen group, of the formula: a

somooon CH3 X on: ons i wherein X stands for hydrogen, CN, CONH or-COOH', to condensation according to one of the usual 'methods andoxidizing the hydroxythionaphthene thus produced so as to form thedesired dyestutf.

We have furthermore found that alsothe products, obtainable bycondensing the new hydroxythionaphthene according to the usual methods,exhibit fastness properties similar 1 to those of the dyestuffobtainable by oxidizring the said hydroxythionaphthene. Y The agrouping: 4o

new dyestufl'sfcontain the following atomic H V The followingexampleillustrates the invention, the-parts being by weight: a a

parts of 3-5-6-trimethylbenzene l-thioglycollic acid-'2-nitrile aredissolved in 1200 parts of'water, 20 parts ofcaustic soda solution oft0Be. and 5 parts ofvsodium sulfide. When dissolution has taken place,there are solution of 40 Be. and thewh ole' is stirred for 2 hours at C.to C. The separation ofthe sodiumsalt of the 4-6-7-trimethyl-3-amino-1-thionaphthene-2-carboxylic acid be gins already on heating thesolutioniand is nearly complete afterkthe additionof parts of sodiumchloride. After filtering by suction and washing with a sodium chloridesolution, the moist paste is dissolved in twenty times its weight ofWater with theaddition of small quantities of caustic soda solution andbisulfite, the whole is filtered, the filtrate is acidified witlrdilutesulfuric acid and heated on the water bath until the formation of thehydroxythionaphthene is completef After cooling, thehydroxythionaphthene is filtered by fsuction, washed and transformedinto the dyestuff accordingto one of the-known method. a;

The 4-6-7-fit-6f-7-hexamethylbisthionaph theneindigo dissolves insulfuric acid to" a green solution. It dissolveswhen being Vatton clearred dyeings of excellent fastness to boiling and extraordinarily goodfastness to light. l

acid-2-nitrile can be preparedkby exchanging in the 1-amino-2-nitro-3-4-6-tri1nethylbenzene the amino group forcyanogene,.reducing'the ni-tro group and exchanging in the1Tcyano-2Tamino-3-4-6-trimethylbenzene thus obtained the amino group.for thefgroup;

SCHQCOOH thods@ 1 a t We claim- I on, a i the said dyestufis yieldingdyeings of excellent fastness properties.

according to one ofthe known "furthermore added partsofcaustic soda tedto a yellow solution andlproduces on cota N a0 1. As new products, vatdyestuffs contain- 2. As new products, Vat dyestuffs of the followingformula:

wherein Y stands for S or NH and Z for hydrogen or any substituent,yielding dyeings of excellent fastness properties.

As new products, vat dyestuffs of the following formula:

u n I /C C Z I I Z CH3 Z wherein Z stands for hydrogen or anysubstituent, yielding dyeings of excellent fastness properties.

4. As new products, vat dyestuffs of the following formula:

(311:; c alkyl 0 o \C=O/ CHz s s \alkyl CH3 a lkyl being red powders,soluble in sulfuric acid to a green solution dissolving when vatted witha yellow coloration and dyeing cotton clear red tints of excellentfastness to boiling and extraordinarily good fastness to light.

5. As a new product, the vat dyestuff of the following formula:

CH3 (H) E (IJHQ o (i 011/ s s orn (1H3 CH3 being a red powder, solublein sulfuric acid to a green solution dissolving when vatted with ayellow coloration and dyeing cotton clear red tints of excellentfastness to boiling and extraordinarily good fastness to light.

In testimony whereof, we affix our signatures.

ERWIN HOFFA. HANS HEYNA.

